Hydrocarbon lakes on Titan

Scientists said on Monday that they have found the first widespread evidence of giant hydrocarbon lakes on the surface of Saturn’s planet-size moon Titan. The cluster of hydrocarbon lakes was spotted near Titan’s frigid north pole during a weekend flyby by the international Cassini spacecraft, which flew within 950 kilometers of the moon.

Researchers counted about a dozen lakes ranging from 10 kms to 100 kms wide. Some lakes, which appeared as dark patches in radar images, were connected by channels while others had tributaries flowing into them.

Several were dried up, but the ones that contained liquid were most likely a mix of methane and ethane.

“It was a real potpourri,” said Cassini scientist Jonathan Lunine of the University of Arizona. Titan is one of two moons in the solar system known to possess a significant atmosphere similar to primordial Earth.

But scientists have long puzzled over the source of its hazy atmosphere rich in nitrogen and methane. Scientists believe methane gas breaks up in Titan’s atmosphere and forms smog clouds that then rain methane down to the surface.

But the source of methane inside the moon, which is releasing the gas into the atmosphere is still unknown, Lunine said. Last year, Cassini found what appeared to be a liquid hydrocarbon lake about the size of Lake Ontario on Titan’s south pole.

But the recent fly-by marked the first time the spacecraft spied a multitude of lakes. Cassini’s next Titan encounter will be on September 7 when it will be 1,000 kms away.

Cassini, funded by NASA and the European and Italian space agencies, was launched in 1997 and took seven years to reach Saturn to explore the ringed planet and its numerous moons.

The mission is managed by NASA’s Jet Propulsion Laboratory based in Pasadena. Cassini’s accompanying probe, Huygens, developed and controlled by the ESA, touched down on Titan in 2005.